This invention relates to the field of adjusters for controlling tension in a belt or web. One known pertinent prior art is commonly owned U.S. Pat. No. 4,660,889, the disclosure of which is incorporated herein by reference and attached hereto.
It is desirable to provide a web adjuster device configured to engage the web in one direction of web travel while allowing travel of the web in the opposite direction of web travel.
The present invention comprises one or more of the following features or combinations thereof. A web adjuster device having a frame with a bottom surface and an opposite top surface defining a first web engaging surface. The frame may include a pair of upstanding side walls extending upwardly away from the first web engaging surface. A web clamping member may be movably mounted to the frame between the pair of side walls, and the web clamping member may define a second web engaging surface and a third web engaging surface separate from the second web engaging surface. A web may extend into a first end of the frame through an opposite second end of the frame, with the web received between the sidewalls and between the first and second web engaging surfaces, and in contact with the third web engaging surface. When the web travels in a first direction through the device, it engages the third web engaging surface to force the second web engaging surface toward the first web engaging surface to trap the web therebetween. When the web travels in a second opposite direction through the device, it engages the third web engaging surface to force the second web engaging surface away from the first web engaging surface to allow web travel in the second opposite direction. The third web engaging surface may be maintained within the frame above the bottom surface of the frame through full range of movement of the web clamping member relative to the frame.
The web clamping member may be pivotally mounted to the frame between the upstanding sidewalls. The web adjuster device may further include a mounting plate defining a top surface and a pair of upstanding sidewalls extending upwardly away from the top surface of the mounting plate, with the mounting plate being mountable to the frame with the top surface thereof in contact with the bottom surface of the frame and with the web clamping member movably mounted between the upstanding sidewalls of the mounting plate. The first web engaging surface of the frame may define a plane, wherein the second opposite end of the frame defines a back wall extending upwardly away from the first web engaging surface and terminating at a top web-engaging edge positioned above the plane. The first and/or second web engaging surfaces may be configured to grip the web as the second web engaging surface of the web clamping member is forced toward the first web engaging surface of the frame. The web clamping member may include a handle portion configured for manual manipulation of the web clamping member.
The web adjuster device may further include a biasing mechanism mounted in contact with the web clamping member and the frame, with the biasing mechanism biasing the second web engaging surface of the web clamping member toward the first web engaging surface of the frame.
The web clamping member may include a protrusion extending toward the back wall of the frame, with the protrusion defining the third web engaging surface of the web clamping member. The web clamping member may alternatively include a protrusion extending downwardly toward the top surface of the frame, with the protrusion defining the third web engaging surface of the web clamping member. The protrusion may be located between the second web engaging surface and the handle portion.
Each of the sidewalls of the frame may define a channel therethrough, and the protrusion of the web clamping member may define a pin on opposite sides thereof, wherein the pins are received within the channels of the sidewalls to thereby limit movement of the web clamping member relative to the frame.
The frame may define a web receiving surface adjacent to a pair of upstanding side walls extending upwardly away from the web receiving surface, with the web receiving surface defining a web engaging protrusion extending away from the web receiving surface. The web traveling in a first direction through this device engages the web engaging surface of the web clamping member to force the web engaging surface of the web clamping member toward the web engaging protrusion of the frame to trap the web therebetween, and the web traveling in a second opposite direction through the device engages the web engaging surface of the web clamping member to force the web engaging surface of the web clamping member away the web engaging protrusion of the frame to allow web travel in the second opposite direction. The device may further include a biasing mechanism mounted in contact with the web clamping member and the frame, with the biasing mechanism biasing the engaging surface of the web clamping member toward the web engaging protrusion of the frame. The web clamping member may be configured such that the web engaging surface of the web clamping member is forced away from the web engaging protrusion of the frame by applying pressure on the handle portion in a direction toward the web receiving surface of the frame. The web clamping member may be alternatively configured such that the web engaging surface of the web clamping member is forced away from the web engaging protrusion of the frame by applying pressure on the handle portion in a direction away from the web receiving surface of the frame.
These and other features and objects of the present invention will become more apparent from the following description of the illustrative embodiments.